package org.apache.solr.analysis;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.TypeTokenFilter;
import org.apache.solr.common.ResourceLoader;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.util.StrUtils;
import org.apache.solr.util.plugin.ResourceLoaderAware;

import java.io.IOException;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Factory class for {@link TypeTokenFilter}.
 * 
 * <pre class="prettyprint" >
 * &lt;fieldType name="chars" class="solr.TextField" positionIncrementGap="100"&gt;
 *   &lt;analyzer&gt;
 *     &lt;tokenizer class="solr.StandardTokenizerFactory"/&gt;
 *     &lt;filter class="solr.TypeTokenFilterFactory" types="stoptypes.txt"
 *                   enablePositionIncrements="true" useWhiteList="false"/&gt;
 *   &lt;/analyzer&gt;
 * &lt;/fieldType&gt;
 * </pre>
 */
public class TypeTokenFilterFactory extends BaseTokenFilterFactory implements
		ResourceLoaderAware {

	// Not until Java6: @Override
	public void inform(ResourceLoader loader) {
		String stopTypesFiles = args.get("types");
		enablePositionIncrements = getBoolean("enablePositionIncrements", false);
		useWhitelist = getBoolean("useWhitelist", false);
		if (stopTypesFiles != null) {
			try {
				List<String> files = StrUtils.splitFileNames(stopTypesFiles);
				if (files.size() > 0) {
					stopTypes = new HashSet<String>();
					for (String file : files) {
						List<String> typesLines = loader.getLines(file.trim());
						stopTypes.addAll(typesLines);
					}
				}
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		} else {
			throw new SolrException(SolrException.ErrorCode.SERVER_ERROR,
					"Missing required parameter: types.");
		}
	}

	private boolean useWhitelist;
	private Set<String> stopTypes;
	private boolean enablePositionIncrements;

	public boolean isEnablePositionIncrements() {
		return enablePositionIncrements;
	}

	public Set<String> getStopTypes() {
		return stopTypes;
	}

	// Not until Java6: @Override
	public TokenStream create(TokenStream input) {
		return new TypeTokenFilter(enablePositionIncrements, input, stopTypes,
				useWhitelist);
	}
}
